Trust on the Tightrope
by ASkyNote
Summary: Reunion Falls version of the episode Not What He Seems. Alternative Universe where Dipper and Mabel were separated since birth. Mabel stayed with her parents and Dipper was sent to live with Grunkle Stan. Twelve years later, when Mabel finds out she has a twin, she makes a trip to Gravity Falls and well, things don't turn out like she expected. Made by sailorleo on tumblr.
**A/N:** This has been sitting in my files for a while now and since NWHS anniversary was this week, I decided to finally post this. It's based of some ask sailorleo received a few weeks, be sure to check out her AU and just general art, it's amazing.

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 **Trust on the Tightrope.**

Even weeks after arriving to town, Mabel never would have thought the biggest mystery was living in the same roof as her. But in Gravity Falls everything was possible, everything was unexpected. She could smell mystery the moment her feet touched the grass of the forest. There were secrets in every corner. She hadn't realized how many were until now.

In the morning, everything had been okay, a warm sunny summer day, having fun with water balloons, without a care in the world.

But then, the agents had showed up, had taken their grunkle away, accused him of stealing toxic waste and insisted that he wasn't who they thought he was. They tried to take them to child services, but Mabel outsmarted them and now, the twins were interfering in the middle of what seemed to be a criminal case, to gather enough evidence and prove Grunkle Stan was not guilty.

The calm before the storm, apparently.

Search for answers, uncover secrets, beat the occasional monster was something she'd gotten used to. But this was a new level of adventure, this was serious. Maybe even more serious than Bill's tricks. The adult world was a complicated thing she wasn't ready to understand yet.

She didn't know Stan for as long as Dipper, but deep in her heart, she _knew_ they were all wrong. Her blunt big old man member of their family was a greedy shoplifter and had no knowledge of morals whatsoever, but he wasn't that kind of a bad guy.

She was going to prove it. To all. Even if 'all' had to include Dipper.

Once again, she wanted to understand her brother's minds, read between the lines, being able to know what he was thinking just by his corporal language. They were twins, they were supposed to do it as easy as breathing - also, maybe some sort of telepathic ability would be absolutely nice - and it pained her that they couldn't because they had just started to act as brother and sister, they didn't have that strong and long relationship built by bonding. They'd been twins by blood since they were born, they'd been _actually_ siblings a few weeks ago.

The best weeks of her entire life.

And everything would be gone if they didn't prove Stan's innocence.

Nevertheless, they weren't doing a great job. How could they? If half of their team seemed to be falling into the pool of distrust, where anger bubbled hotter than boiled water.

But it was all a misunderstanding. She was one hundred percent _sure_ of it.

Mabel wondered if she would feel the same, being in Dipper's shoes, if she was in another world, where she didn't feel like an outsider on her own family. But this Mabel couldn't formulate that thought, because this Mabel didn't want to lose the family she'd gained and had tried so hard to fit in.

But she would be lying if she said she didn't falter when she saw the fake IDs, when Dipper read the header of an old newspaper declaring that Stan Pines had died, when the words 'global destruction' were showed up in a bright purple light.

Their priorities changed immediately and they ended up with Soos, Dipper and her around the red button, the countdown echoing in the basement, Dipper's hand lowering and-

Grunkle Stan screamed.

He was panting, he was probably escaping from the police. Mabel didn't know if she was relieved or not that he was going to see whatever plan he had coming to an end.

Dipper's eyes met hers - for support, for trying to exchange some thoughts, she couldn't tell - but there was nothing she could say to him. Mabel, for the first time, was speechless. Watching her two favorite people in the world fighting left her absolutely heartbroken.

"Dipper, you gotta trust me!"

"How can I trust you?! After you promised me you wouldn't hide anything else? After you've lied to us-lied to _me_ , all my life?!"

Both sides were right, both sides were wrong.

 _T minus thirty-five seconds._

And suddenly, they were floating. Mabel managed to hold on in a wooden support. Dipper was clinging on the base of the button for dear life. He was about to press it when Stan and Soos started wrestling.

She didn't pay attention to them, just catching a few words between all the yelling.

"-you an order!"

"-have a new mission now. Protecting these kids!"

Mabel was focused on Dipper, wishing she could wrap him in a hug, the kind of hug where he would whine and struggle to let go.

Dipper shut down his eyes, his knuckles were gripping the base, turning white. He was shaking. He was having a fight inside his head.

She wasn't going to let him fight alone.

Mabel found her voice.

"Dipper! It's okay! Do what you think is right. Trust in yourself!"

"But…but what if I don't know what's right?" he choked, and Mabel could've swore he'd never looked so conflicted, so confused.

 _T-minus twenty seconds._

The portal flashed for the second time, pushing Stan, Soos and her against the wall. Mabel's back hit a tube and that would surely bruise later.

"Yes you do! Listen to your intuition, your heart! The answer is right there! It's always there!"

If she'd learned anything about him this summer, it was that, when he followed his instinct, when he was confident on what he sensed was correct, the results turned out good.

"Dipper, look at me," Stan called out, pleading. Dipper raised his gaze and he stared at him, teary, _hurt_. "I know I have made a lot of mistakes, I know I could've handled your situation better. But listen to me, I care about you and Mabel, I never thought I would as much as I do. Dipper, you've known me your entire life. Do you really think I'm the bad guy?"

She could sense Grunkle Stan's desperation, it was reflecting on his eyes, his words.

 _Ten._ _Nine._

Dipper was biting his lip. The hand coming down to hit the button trembled.

"Dipper, please!"

 _Six. Five._

Dipper looked at her and Mabel nodded. She didn't know what he was going to do, she didn't know what was running through his mind, but whatever decision he'd chosen, Mabel supported him, because that was what family did, right?

 _Four. Three._

Without saying a word, he let go.

The counter hit zero.


End file.
